JP2001124971A - Zoom lens barrel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a zoom lens barrel having superior strength in terns of a simple and small-sized constitution. SOLUTION: In this zoom lens barrel provided with a rotary delivery cylinder moved back and forth in an optical axis direction when rotationally drive, a straight advance cylinder positioned on the inner side of the rotary delivery cylinder and guided straight in the optical axis direction and a connection means for connecting the straight advance cylinder to the rotary delivery cylinder, so as to be freely relatively rotated and not to relatively move in the optical axis direction, the connection means is provided with at least two peripheral direction grooves, whose center is an optical axis provided on different positions in the optical axis direction on one of the inner peripheral surface of the rotary delivery cylinder and the outer peripheral surface of the straight advance cylinder and at least two engaging claws projected in the radial direction at different positions in the optical axial direction corresponding to at least two peripheral direction grooves on the other one of the inner peripheral surface of the rotating delivery cylinder and the outer peripheral surface of the straight advance cylinder and respectively engaged with the peripheral direction grooves to slide in the peripheral direction and not to relatively move in the optical axis direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a zoom lens barrel.

[0002]

2. Description of the Related Art In a zoom lens barrel of a zoom compact camera or the like, a rotating barrel (rotating barrel) that can be rotated and extended with respect to a camera body and a rotation-adjusted straight-moving cylinder located inside the rotating cylinder are provided. In many cases, a structure in which relative rotation is allowed and the body is integrally moved in the optical axis direction is used. Generally, such a rotary cylinder and a straight-moving cylinder are relatively rotatably guided by an engagement relationship between a claw or a flange provided at a rear end in the optical axis direction and a circumferential groove. Although it is relatively easy to secure the strength on the side, it is difficult to obtain sufficient strength on the front end side. For example, if a through-groove is formed in the straight-moving cylinder for the purpose of giving rotation to another rotary feeding cylinder further provided inside the straight-moving cylinder, the strength of the straight-moving cylinder is reduced by providing this through-groove, and particularly at the front end side. It becomes easy to fall in the direction approaching the optical axis. If the rectilinear barrel falls, the imaging optical system will be out of order. In order to solve the above-mentioned problems, in the conventional zoom lens barrel, the entire barrel is made thicker, the length of the barrel without the through groove is increased, or the rotating barrel and the straight-moving barrel are used. For example, a reinforcing ring was attached to the front end of the lens, which caused an increase in the size of the lens barrel and an increase in the number of parts.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a zoom lens barrel which has a simple and compact structure but has excellent strength.

[0004]

SUMMARY OF THE INVENTION The present invention is directed to a rotary feeding cylinder which advances and retreats in the direction of the optical axis when driven to rotate; a linear pipe located inside the rotary feeding cylinder and guided straight in the optical axis direction; And a coupling means for coupling relative to the rotary feeding cylinder so as to be freely rotatable and impossible to move relative to the optical axis direction, wherein the coupling means is linear with the inner peripheral surface of the rotary feeding cylinder. At least two of which are provided on one of the outer peripheral surfaces of the cylinder at different positions in the optical axis direction and center on the optical axis.
Two circumferential grooves; the other of the inner circumferential surface of the rotary feeding cylinder and the outer circumferential surface of the rectilinear barrel, which are radially projected at different positions in the optical axis direction corresponding to the at least two circumferential grooves. And at least two engaging claws which are respectively slidable in the circumferential direction and relatively immovable in the optical axis direction in the circumferential grooves. In this zoom lens barrel, since the connecting portion between the rotary feeding cylinder and the straight-moving barrel is constituted by a plurality of circumferential grooves and engagement claws provided at different positions in the optical axis direction, the strength of the connection is high, The required strength can be ensured over the entire length of the lens barrel in the optical axis direction without increasing the thickness of the cylinder, increasing the length in the optical axis direction, or providing a reinforcing ring or the like.

[0005] In order to obtain high strength, the two circumferential grooves are located before and after the center of the length in the optical axis direction of the rotary feeding cylinder or the straight moving cylinder in which the circumferential grooves are formed. Is preferred. Further, in a case where the above-mentioned engaging claw is provided on a straight-moving cylinder and the straight-moving cylinder has a through groove inclined with respect to the optical axis, at least two engaging claws can It is preferable to be located before and after the groove. In addition, it is preferable that a plurality of concentric engaging claws are provided at different positions in the circumferential direction corresponding to the respective circumferential grooves.

Further, from the viewpoint of facilitating assembly and disassembly, the at least two circumferential grooves are formed on the inner peripheral surface of the rotary feeding cylinder, and the at least two engaging claws are formed on the outer peripheral surface of the rectilinear cylinder. In addition, the inner peripheral surface of the rotary feeding cylinder further communicates in parallel with the optical axis from the rear end to the circumferential groove located at the front of the optical axis, and a specific relative rotation between the rotary feeding cylinder and the straight-moving cylinder is performed. It is preferable that a claw insertion / removal groove is formed at the position so that at least two engagement claws can be inserted / removed in the optical axis direction with respect to the at least two circumferential grooves.

The claw insertion / removal groove, which is parallel to the optical axis and intersects with the circumferential groove, is formed on the same circumferential surface of the inner circumferential surface of the rotary feeding cylinder or the outer circumferential surface of the straight-moving cylinder. When a different optical axis direction groove is formed, the circumferential length of the engaging claw is preferably larger than the width of the optical axis direction groove. With this configuration, it is possible to prevent the engaging claws from falling off from places other than the claw insertion / recess grooves.

The present invention is also directed to a zoom lens barrel having a pair of cylindrical members having different diameters which are coupled to each other so that relative rotation is free and relative movement in the optical axis direction is impossible. The coupling means for coupling is provided on one of the inner peripheral surface of the large-diameter cylindrical member and the outer peripheral surface of the small-diameter cylindrical member at different positions in the optical axis direction. At least two circumferential grooves; and at least one of the inner circumferential surface of the large-diameter tubular member and the outer circumferential surface of the small-diameter tubular member positioned in the optical axis direction corresponding to the at least two circumferential grooves. At least two engaging claws, each of which is slidable in the circumferential direction and relatively immovable in the optical axis direction in the circumferential grooves. Features.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A zoom lens barrel 10 is provided on a camera body (not shown) of a zoom compact camera, and includes a relative distance between a first lens unit L1 and a second lens unit L2, and each lens unit. Is changed by changing the distance from the film surface, and focusing is performed by moving the first lens unit L1 along the optical axis O. First, the overall structure and operation of the zoom lens barrel 10 will be described mainly with reference to FIGS. The expression “optical axis direction” in the following description is used to mean a direction parallel to the imaging optical axis. Further, the expression “peripheral direction” is used to mean a circumferential direction around the photographing optical axis.

A fixed lens barrel 13 is provided in a camera body (not shown).
Has been fixed. On the inner peripheral surface of the fixed lens barrel 13, a female helicoid 14 is formed, and further, a straight guide groove 15 parallel to the optical axis O is formed. Although a plurality of the straight guide grooves 15 are provided at different positions in the circumferential direction of the fixed lens barrel 13, only one is partially shown in FIGS. 1 and 2. Although not shown, the fixed lens barrel 13 is formed with a long cutout in a direction parallel to the optical axis O, and the tooth surface of the zoom gear 11 is exposed inward from the cutout. The zoom gear 11 has an optical axis O by a zoom motor M.
This is a gear that is turned around an axis that is parallel to.

The female helicoid 14 of the fixed lens barrel 13 is screwed with a male helicoid 18 formed near the rear end of the outer peripheral surface of a first rotary cylinder (rotary feeding cylinder) 17. In the first rotary cylinder 17, a part of the thread of the male helicoid 18 is further formed to be wide, and the outer peripheral gear 19 is provided on the wide thread. As shown in FIG. 5, the teeth of each outer peripheral gear 19 are formed in a direction parallel to the optical axis O, and the zoom gear 11 is meshed with the teeth. A pair of bottomed linear cam grooves (optical axis direction grooves) 16 parallel to the optical axis are formed on the inner peripheral surface of the first rotary cylinder 17 at positions substantially symmetrical with respect to the optical axis O. I have. Each straight cam groove 1
6 has an opening facing the rear end face of the first rotary cylinder 17.

Inside the first rotary barrel 17, a first straight barrel (straight barrel) 20 is provided. The first straight cylinder 20
Is coupled to the first rotary cylinder 17 so that it can rotate relatively around the optical axis O and does not relatively move in a direction along the optical axis O by a configuration described later. A plurality of rectilinear guide projections 24 (only one is shown in FIGS. 1, 2 and 4) are arranged on the outer peripheral surface near the rear end of the first rectilinear cylinder 20 at predetermined intervals in the circumferential direction. It protrudes in the direction. Each rectilinear guide projection 24 is slidably engaged with the rectilinear guide groove 15 formed on the inner peripheral surface of the fixed lens barrel 13. Accordingly, the first rectilinear barrel 20 is moved integrally with the first rotary barrel 17 in the direction along the optical axis O, but in the circumferential direction around the optical axis O, the relative rotation with respect to the fixed barrel 13 is made. Regulated. That is, the vehicle is guided straight ahead.

The first rotary barrel 17 and the first rectilinear barrel 20 constitute a first extension step portion of the zoom lens barrel 10. The first feeding stage is driven by a zoom motor M by a zoom gear 1.
1 is rotated in a predetermined lens barrel extending direction, the outer peripheral gear 19 is rotated.
The first rotary cylinder 17 is rotated through the female helicoid 14
The first rotating barrel 17 is extended from the fixed barrel 13 while rotating due to the relationship between the first rotating barrel 17 and the male helicoid 18. At the same time, the first rectilinear barrel 2 rotatably supported with the first rotary barrel 17
0 moves back and forth along the optical axis O together with the first rotating barrel 17 while being guided straight to the fixed lens barrel 13. Note that the zoom gear 11 is formed of a multiple pinion or the like that is long in the optical axis direction. Even when the first rotary cylinder 17 is extended, the engagement between the outer peripheral gear 19 and the zoom gear 11 does not come off.

A female helicoid 27 in the same direction as the female helicoid 14 is formed on the inner peripheral surface of the first rectilinear barrel 20. Further, on the inner peripheral surface of the first rectilinear barrel 20, rectilinear guide grooves 28 are formed at predetermined intervals in the circumferential direction so as to be parallel to the optical axis O. A plurality of the straight guide grooves 28 are provided at different positions in the circumferential direction of the first straight barrel 20, but only one is shown in FIGS.

The first rectilinear barrel 20 is further formed with two through grooves 25 penetrating the inner peripheral surface and the outer peripheral surface.
As shown in FIG. 5, the two through grooves 25 are formed parallel to each other so as to be substantially parallel to the threads of the female helicoid 27, and are inclined with respect to the optical axis O.

Inside the first rectilinear barrel 20, there is provided a second helicoid 29 having a male helicoid 29 screwed to the female helicoid 27 on its outer peripheral surface.
The rotating cylinder 30 is provided. The male helicoid 29 is provided near the rear end of the outer peripheral surface of the second rotary cylinder 30. As shown in FIG. 4, on the outer peripheral surface near the rear end of the second rotary cylinder 30,
A pair of cylindrical support pins 30a are protruded by cutting out a part of the male helicoid 29 (only one is shown in FIGS. 3 and 4), and a pair of support pins 30a is provided for the pair of support pins 30a. A cam projection 31 is attached. Each cam projection 31
Penetrates a through groove 25 formed in the first rectilinear barrel 20, and further has a distal end engaged with a linear cam groove 16 formed on the inner peripheral surface of the first rotary cylinder 17 in the optical axis direction. Therefore, when the first rotary cylinder 17 is rotated in response to the drive of the zoom motor M, a rotational force is applied to the second rotary cylinder 30 via the cam projection 31 that engages with the linear cam groove 16. When this rotational force is applied, the second rotary cylinder 30 is fed forward from the first rectilinear cylinder 20 while rotating in the same direction as the first rotary cylinder 17 due to the engagement relationship between the male helicoid 29 and the female helicoid 27. . Since the cam projection 31 penetrates the through groove 25 parallel to the female helicoid 27, the cam groove 31 is moved along with the extension operation.
Move within 5. Conversely, when the first rotary cylinder 17 is rotated in the storage direction, the second rotary cylinder 30 is
While moving in the same direction as the first moving cylinder 20.

Inside the second rotary cylinder 30, there is provided a second rectilinear cylinder 3
3 are provided. The second rectilinear barrel 33 has a rear flange portion 33a and three rectilinear guide portions 33b extending forward in the optical axis direction from the rear flange portion 33a. An annular groove 34 centering on the axis O is formed. On the other hand, an engagement claw 32 is provided on the inner peripheral surface of the second rotary cylinder 30 so as to project therefrom.
4, the second rotary cylinder 30 and the second straight cylinder 3
3 is relatively immovable in a direction along the optical axis O, and is relatively rotatable. The pawl engagement can be disengaged at a specific rotation angle position.

A plurality of rectilinear guide projections 36 are provided on the outer peripheral surface near the rear end of the second rectilinear barrel 33 at different positions in the circumferential direction so as to protrude outward in the radial direction. Each of the rectilinear guide projections 36 is slidably engaged with a rectilinear guide groove 28 formed on the inner peripheral surface of the first rectilinear cylinder 20. Thereby, the second straight barrel 33 is guided straight through the first straight barrel 20.

The above-described second rotary cylinder 30 and second rectilinear cylinder 33
Constitute the second extension step portion of the zoom lens barrel 10.
As described above, the first rotary cylinder 1 constituting the first feeding step portion
7 rotates and is extended from the fixed barrel 13, the second rotating barrel 30 rotates in the same direction as the rotation direction of the first rotating barrel 17 with respect to the fixed barrel 13, It is paid out from. At the same time, since the second rectilinear barrel 33 is coupled to the second rotary barrel 30 so as to be able to rotate only relative thereto, the second rectilinear barrel 33 is guided straight by the first rectilinear barrel 20 by the relationship between the rectilinear guide protrusion 36 and the rectilinear guide groove 28, Optical axis O with two-rotation cylinder 30
Move along.

A third straight barrel 50 is located between the second rotary barrel 30 and the second straight barrel 33. Third straight barrel 50
Unlike the second rectilinear barrel 33 having a partial peripheral shape, has a complete cylindrical peripheral surface that constitutes the appearance of the zoom lens barrel 10. Inside the third rectilinear barrel 50, a shutter block 35 is fixed via a rectilinear guide ring 60. The shutter block 35 supports the first lens unit L1. The first lens group L1 is supported by a shutter block 35 via a focusing helicoid 35a. When a focusing motor (not shown) built in the shutter block 35 is driven, the first lens group L1 is moved according to the focusing helicoid 35a. L1 moves back and forth along the optical axis O while rotating, so that focusing can be performed.

A rectilinear guide ring 60 is fixed to the rear of the shutter block 35. On the rectilinear guide ring 60, three first rectilinear guide grooves 61 and three second rectilinear guide grooves 62 are formed alternately in the circumferential direction. Each straight guide groove 61 has a second straight barrel 3
Each of the three rectilinear guide portions 33b provided in 3 is fitted. The third rectilinear barrel 50 (shutter block 35) and the rectilinear guide ring 60 are guided rectilinearly in the optical axis direction by the fitting relationship between the rectilinear guide groove 61 and the rectilinear guide portion 33b. In addition, three clearance grooves 51 (only one is shown in FIGS. 2 and 3) in the optical axis direction are provided on the inner peripheral surface of the third rectilinear motion cylinder 50 at circumferential positions corresponding to the first rectilinear guide grooves 61. Is formed. The escape groove 51 is a groove for preventing the rectilinear guide portion 33b guided by the rectilinear guide ring 60 from interfering with the third rectilinear barrel 50.

From the outer peripheral surface near the rear end of the third rectilinear barrel 50, the three first rollers 38A are located at different positions in the circumferential direction.
Is protruding. Third straight barrel 50 and straight guide ring 60
The rear ends of the first rollers 38A overlap each other, and the radially inner end of the first roller 38A penetrates the third rectilinear barrel 50 at this overlap portion, and the linear guide ring 60
The third rectilinear barrel 50 and the rectilinear guide ring 60 are connected so that they do not relatively move in the optical axis direction or the circumferential direction. On the other hand, a radially outer end of the first roller 38 </ b> A is formed in the first group guide groove 3 formed on the inner peripheral surface of the second rotary cylinder 30.
9A is slidably fitted. The first group guide groove 39A has a predetermined inclination with respect to the optical axis O, and
When the first roller 38A rotates, the first roller 38A is guided by the first group guide groove 39A. As a result, the third rectilinear barrel 50 guided straight through the second rectilinear barrel 33 is illuminated with respect to the second feeding step. It is moved back and forth in the axial direction. In other words, the third rectilinear advancing barrel 50 constitutes the third extension step of the zoom lens barrel 10. The first lens unit L1 includes the third rectilinear barrel 5
It moves in the optical axis direction together with 0.

The second linear guide groove 62 of the linear guide ring 60 has a second group support frame 37 for supporting the second lens group L2.
The three rectilinear guide portions 37a provided in the above are slidably fitted. The linear guide portion 37a and the second linear guide groove 6
The second group support frame 37 is guided linearly by the fitting relationship of 2. A second roller 38 </ b> B protrudes radially outward from each of the rectilinear guide portions 37 a of the second group support frame 37, and the second roller 38 </ b> B is formed on the inner peripheral surface of the second rotary cylinder 30. The second group guide groove 39B is slidably fitted. The second group guide groove 39B has a predetermined inclination with respect to the optical axis O, and when the second rotary cylinder 30 rotates, the second roller 38 is guided by the second group guide groove 39B, and as a result, is guided straight. The rear group support frame 37 and the second lens group L2 are moved back and forth in the optical axis direction within the second rectilinear barrel 33. Note that FIG. 1 shows only the first roller 38A because the first roller 38A and the second roller 38B are positioned so as to overlap in the circumferential direction.

The above-described zoom lens barrel 10 operates as follows. When the zoom motor M is driven in the extending direction, the first rotating barrel 17 is rotated and unreeled from the fixed barrel 13, and the first rectilinear barrel 20 is guided by the fixed barrel 13 in a straight line. And move forward. Then
The second rotary cylinder 30 is fed out of the first straight cylinder 20 while rotating in the same direction as the rotation direction of the first rotary cylinder 17, and at the same time,
The second rectilinear barrel 33 moves straight along the optical axis O together with the second rotary barrel 30. When the second rotary cylinder 30 is rotated and fed, the first group guide groove 39A formed on the inner periphery of the second rotary cylinder 30
As a result, the third rectilinear barrel 50 is further moved forward along the optical axis together with the first lens unit L1. At the same time, the second lens unit L2
Is guided by the second group guide groove 39B, so that the second rotary cylinder 3
0 moves in a predetermined locus. Accordingly, the first lens unit L1 and the second lens unit L2 are moved as a whole forward of the optical axis while relatively changing the distance between each other. Conversely, when the zoom motor M is driven in the storage direction, the zoom lens barrel 10 performs the reverse operation. As described above, the zoom lens barrel 10 including the three-stage extending portion has a combined operation of changing the distance between the first lens group L1 and the second lens group L2 with respect to the film surface and the relative movement of each lens group. Perform zooming with. Further, at each focal length changed by zooming, focusing is performed by displacing the first lens unit L1 in a direction parallel to the optical axis O.

Next, a configuration according to the features of the present invention will be described. As described above, the first rotary barrel 17 and the first rectilinear barrel 20 can rotate relative to each other about the optical axis O.
Although they are coupled so that relative movement in the direction along the optical axis O is impossible, the coupling structure is as follows.

At the rear end of the first straight barrel 20, there is provided a first straight barrel 2
The rear end rib 40 is provided with a diameter larger than that of the main body of the first straight-moving cylinder 20 slightly ahead of the rear end rib 40.
Two rear engaging claws 41 (41
A, 41B). In addition, on the outer peripheral surface of the first rectilinear barrel 20 ahead of this, each rear engaging claw 41A,
Two front engagement claws 4 in a circumferential direction corresponding to 41B.
2 (42A, 42B) are provided. 4 and 5
As shown in the figure, the combination of the rear engagement claw 41A and the front engagement claw 42A and the combination of the rear engagement claw 41B and the front engagement claw 42B whose positions are different in the optical axis direction respectively have the through groove 25. It is arranged so as to be located before and after in the optical axis direction with the interposition therebetween. Each of the engaging claws 41 and 42 is formed to have the same length in the circumferential direction.
The circumferential length of 1, 42 is larger than the circumferential width of the linear cam groove 16 formed on the inner circumferential surface of the first rotary cylinder 17.

On the other hand, a rear annular groove (circumferential groove) 44 is formed on the inner peripheral surface of the first rotary cylinder 17 near the rear end, and a front annular groove (circumferential direction) is provided forward of the rear annular groove 44. Groove) 4
5 are formed. Rear annular groove 44 and front annular groove 45
Are annular bottomed grooves formed in a parallel plane orthogonal to the optical axis O, and are disposed so as to be located before and after the center of the length of the first rotary cylinder 17 in the optical axis direction. . The distance between the rear annular groove 44 and the front annular groove 45 in the optical axis direction corresponds to the distance between the rear engagement claw 41 and the front engagement claw 42 provided on the first rectilinear barrel 20 side.

The width of the rear engaging claw 41 in the optical axis direction does not rattle with respect to the rear annular groove 44 in the optical axis direction.
It is set to the extent that it can slide in the circumferential direction. Similarly,
The width of the front engagement claw 42 in the optical axis direction is set to such a degree that the front engagement claw 42 can slide in the circumferential direction without rattling with respect to the front annular groove 45 in the optical axis direction.

Further, the inner peripheral surface of the first rotary cylinder 17 is formed in a direction parallel to the optical axis
4, two bottomed claw insertion / removal grooves 47A and 47B communicating with the front annular groove 45 are formed. Claw insertion groove 47
The rear ends of A and 47B are openings facing the rear end surface of the first rotary cylinder 17.

The claw insertion / removal grooves 47A and 47B are respectively provided in the circumferential direction with the rear engagement claw 41A and the front engagement claw 42A.
, The rear engagement claw 41B and the front engagement claw 4
2B. The circumferential width of each of the claw insertion / removal grooves 47A and 47B is
A, 41B, 42A, and 42B are slightly larger than the circumferential length, and these engaging claws can move in the respective claw insertion / removal grooves 47A, 47B in the optical axis direction.

When the first rotary cylinder 17 and the first rectilinear cylinder 20 are combined, the first engagement claws 42A and 42B are so arranged as to correspond to the claw insertion / removal grooves 47A and 47B, respectively.
After adjusting the rotational positions of the rotary cylinder 17 and the first rectilinear cylinder 20, the arrow S in FIG.
The first rectilinear barrel 20 is inserted in the direction. Then, first, the front engagement claws 42A, 42B are respectively inserted into the claw insertion / removal grooves 47A, 47B.
And the insertion operation is continued, the rear engagement claw 41
A and 42B enter nail insertion grooves 47A and 47B, respectively. In the first rectilinear barrel 20, the rear engagement claws 41A, 41
The rear end rib 40 is provided behind the first rotary cylinder 17 immediately after the rear engagement claws 41A and 42B enter the claw insertion / removal grooves 47A and 47B. The further insertion operation is restricted by contacting the end face.

At the time of the insertion regulation, in the optical axis direction,
The pair of rear engagement claws 41 (41A, 41B) are located at positions corresponding to the rear annular grooves 44, and the pair of front engagement claws 42 (4
2A and 42B) are located at positions corresponding to the front annular groove 45, and the first rotary cylinder 17 and the first rectilinear cylinder 20 can be relatively rotated by the engagement relationship between the front and rear annular grooves and the engagement claws.
The first rotary cylinder 17 and the first rectilinear cylinder 2
When each of the engagement claws is slightly rotated relative to each other,
The first linear cylinder 20 cannot be pulled out from the first rotary cylinder 17 because the first linear cylinder 20 is separated from the first and second rotary cylinders 17 because the first linear cylinder 20 is separated from the first rotary cylinder 17. That is, the first rotary cylinder 17 and the first rectilinear cylinder 20 can be relatively rotated around the optical axis O, and are relatively immovably coupled in a direction along the optical axis O. To release the connection between the first rotary cylinder 17 and the first rectilinear cylinder 20, the engaging claws 41A and 42A are located in the claw inserting / removing groove 47A, and the engaging claws 41B and 42B are After rotating the first rotary cylinder 17 and the first rectilinear barrel 20 to a rotational position where the claw insertion / removal groove 47B can be inserted and removed, the first rectilinear barrel 2
You only have to pull 0 back.

At the time of assembling, the second rotary cylinder 30 may be incorporated into the first linear cylinder 20 before the first rotary cylinder 17 and the first linear cylinder 20 are combined. The second rotary cylinder 30 is provided with a pair of cam projections 31,
When the rotary cylinder 30 is incorporated into the first rectilinear cylinder 20, the pair of cam projections 31 penetrate the corresponding through-grooves 25, and their tips project radially outward. Subsequently, as described above, the rotation positions of the first rotary cylinder 17 and the first rectilinear cylinder 20 are adjusted so that each front engagement claw 42 corresponds to each claw insertion / recess groove 47. Here, a pair of cam projections is used. The rotational position of the second rotary cylinder 30 in the first rectilinear barrel 20 is also adjusted so that the position of 31 corresponds to the pair of linear cam grooves 16. When the first rectilinear barrel 20 is inserted in the S direction in FIG. 4, a pair of cam projections 31 projecting outward in the radial direction are inserted into the corresponding linear cam grooves 16 from the rear end side of the first rotary barrel 17. Is done.

Each of the rear annular groove 44 and the front annular groove 45 intersects with the straight cam groove 16 for guiding the cam projection 31, and the inside of each annular groove 44, 45 engages with the engaging claw 4.
When the reference numerals 1 and 42 slide, the respective engagement claws 41 and 42 pass through the intersection with the straight cam groove 16. However, as described above, since the circumferential length of each of the engaging claws 41 and 42 is larger than the circumferential width of the linear cam groove 16, the first
When the rotary barrel 17 and the first rectilinear barrel 20 rotate relative to each other, the engaging claw 4
1, 42 do not fall off from the annular grooves 44, 45 at the straight cam groove 16 portion.

The magnitude of the relative rotation angle at which the first rotary barrel 17 and the first rectilinear barrel 20 are kept in a state in which they cannot be inserted into and removed from each other in the optical axis direction. What is necessary is just to determine arbitrarily in the range required for extension and storage of the lens barrel 10. For example, in the present zoom lens barrel 10, the claw insertion / removal grooves 47A and 47B are not arranged at symmetrical positions with respect to the optical axis O in the circumferential direction. The combination of the dowel 41B and the combination of the front engagement claw 42A and the front engagement claw 42B are also arranged so as not to be symmetrical in the circumferential direction. Therefore, except for the rotation position for insertion and removal described above, the rear engagement claw 41A and the front engagement claw 42A, or the rear engagement claw 41B
And at least one of the combinations of the front engagement claw 42B is engaged with the rear annular groove 44 and the front annular groove 45, so that the first rotary cylinder 17 and the first rectilinear cylinder 20 are in principle The relative rotation angle of the first rotary cylinder 17 and the first rectilinear cylinder 20 may be smaller than this, although the relative rotation can be performed in a retaining state to nearly 360 degrees. From the viewpoint of the coupling strength of the lens barrel member, it is desirable to set the relative rotation angle within a range where all four engagement claws are maintained in the state of being engaged with the corresponding annular grooves.

In this embodiment, all the engaging claws and the claw inserting / removing grooves have the same circumferential width, but the engaging claws and the claw inserting / removing grooves located at different positions in the circumferential direction have different widths. The configuration may be such that the circumferential width and the radial engagement depth are not uniform. With this configuration,
The relative rotation angle of the lens barrel in a state where all the engagement claws are engaged with the corresponding annular grooves can be made large.

According to the above described lens barrel coupling structure, the first rotary cylinder 17 and the first rectilinear cylinder 20 are in the engagement relationship of the rear engagement claws 41 (41A and 41B) with the rear annular groove 44 on the rear end side. In addition, the front engaging claw 4 is engaged with the front annular groove 45 in front of the optical axis.
2 (42A and 42B) also have an engagement relationship, and thus are superior in strength as compared with the case where only the rear end is joined. Conventionally, in order to obtain such strength of the lens barrel, the lens barrel is made thicker, if there is a cam groove or a through groove, the length in the optical axis direction is increased, or the front end of the rotary feeding cylinder and the straight moving cylinder is used. A reinforcing ring and the like are mounted on the lens barrel, which results in an increase in the size of the lens barrel and an increase in the number of parts. Sufficient strength can be obtained. In particular, in the present embodiment, the through-groove 2 penetrating through the inner and outer peripheral surfaces of the first rectilinear barrel 20 is provided.
5 is formed, it is easy for the portion to fall or to be distorted in a portion ahead of the through groove 25, so that the coupling structure according to the present invention is useful.

However, the present invention is not limited to the illustrated embodiment. For example, in the embodiment, the first rotary cylinder 17
A circumferential groove is provided on the side, and an engagement claw is provided on the first rectilinear barrel 20 side. This is because the first rectilinear barrel 20 is thinner than the first rotary cylinder 17 and the through-groove 25 is provided on the first rectilinear barrel 20 side. For reasons of weakness, depending on the case, a circumferential groove may be provided on the straight-moving cylinder side and an engaging claw may be provided on the rotary feeding cylinder side. In the illustrated embodiment, the number of circumferential grooves (and corresponding engaging claws) formed at different positions in the optical axis direction is two, but three or more may be provided.

Further, contrary to the embodiment, the lens barrel member that moves straight is located outside in the radial direction with a large diameter, and the lens barrel member that rotates with a small diameter is provided inside the lens barrel member. Even so, the present invention can be applied. In other words, as long as a pair of cylindrical members that can be rotated relative to each other and cannot be moved in the optical axis direction are connected, a plurality of circumferential grooves whose positions are different in the optical axis direction are used. By using a coupling structure having an engagement claw that engages with the lens, it becomes easy to secure the strength of the lens barrel with a simple configuration without increasing the size.

[0040]

As is apparent from the above description, according to the present invention, it is possible to obtain a zoom lens barrel which has a simple and compact structure but is excellent in strength.

[Brief description of the drawings]

FIG. 1 is a side sectional view of a zoom lens barrel according to an embodiment of the present invention in a housed state.

FIG. 2 is a side sectional view showing a state where the zoom lens barrel of FIG. 1 is extended to a wide end.

FIG. 3 shows a second one of the zoom lens barrels of FIGS. 1 and 2;
It is a perspective view which decomposes | disassembles and shows the internal component from a rotary cylinder.

FIG. 4 is a diagram showing a first example of the zoom lens barrel shown in FIGS. 1 and 2;
It is a perspective view which decomposes | disassembles and shows a rotating cylinder, a 1st linear moving cylinder, and a 2nd rotating cylinder.

FIG. 5 is an expanded view of a first rotary cylinder and a first rectilinear cylinder.

[Explanation of symbols]

 Reference Signs List 10 zoom lens barrel 13 fixed barrel 16 linear cam groove (groove in optical axis direction) 17 first rotating barrel (rotary feeding cylinder) 20 first straight barrel (straight barrel) 25 through groove 30 second rotating barrel 31 cam projection 33 Second rectilinear barrel 40 Rear end rib 41 (41A 41B) Rear engagement claw 42 (42A 42B) Front engagement claw 44 Rear annular groove (circumferential groove) 45 Front annular groove (circumferential groove) 47A 47B Claw insertion / removal groove 50 3rd straight barrel

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiromitsu Sasaki 2-36-9 Maeno-cho, Itabashi-ku, Tokyo Asahi Gaku Kogyo Co., Ltd. (72) Inventor Kazunori Ishizuka 2-36, Maeno-cho, Itabashi-ku, Tokyo No. 9 Asahi Gaku Kogyo Co., Ltd. F-term (reference) 2H044 BD08 BD09 DA02

Claims (7)

[Claims] 1. A rotary feeding cylinder that advances and retreats in the optical axis direction when driven to rotate; a straight-moving cylinder positioned inside the rotary feeding cylinder and guided straight in the optical axis direction; A coupling means for coupling relative to the cylinder so as to be freely rotatable and impossible to move relative to the optical axis direction, wherein the coupling means comprises an inner peripheral surface of the rotary feed-out cylinder and an outer peripheral surface of the rectilinear cylinder. At least two circumferential grooves centered on the optical axis provided at different positions in the optical axis direction; and at least one of the inner peripheral surface of the rotary feeding cylinder and the outer peripheral surface of the straight-moving cylinder, Protruding radially at different positions in the optical axis direction corresponding to the two circumferential grooves. Each of the circumferential grooves is slidable in the circumferential direction and is relatively immovable in the optical axis direction. And at least two engaging claws. 'S barrel. 2. The zoom lens barrel according to claim 1, wherein the at least two circumferential grooves are located before and after the center of the optical axis length of the rotary feeding cylinder or the straight-moving cylinder in which the circumferential grooves are formed. The zoom lens barrel that is located. 3. The zoom lens barrel according to claim 1, wherein the at least two engaging claws are provided on the rectilinear barrel, and the rectilinear barrel has a through groove inclined with respect to an optical axis; The zoom lens barrel, wherein the at least two engaging claws are positioned before and after the through groove in the optical axis direction. 4. The zoom lens barrel according to claim 1, wherein a plurality of concentric engagements whose positions are different in a circumferential direction correspond to each of said at least two circumferential grooves. Zoom lens barrel with claws. 5. The zoom lens barrel according to claim 1, wherein said at least two circumferential grooves are formed on an inner circumferential surface of a rotary feeding cylinder, and said at least two engaging claws are rectilinear. It is formed on the outer peripheral surface of the cylinder, and further communicates in parallel with the optical axis from the rear end to the circumferential groove located closest to the optical axis on the inner peripheral surface of the rotary feeding cylinder,
A claw insertion / removal groove is formed at a specific relative rotation position between the rotary feeding cylinder and the straight-moving cylinder so that the at least two engagement claws can be inserted into and removed from the at least two circumferential grooves in the optical axis direction. Zoom lens barrel. 6. The zoom lens barrel according to claim 5, wherein the inner peripheral surface of the rotary feed-out barrel or the outer peripheral surface of the rectilinear barrel has the same peripheral surface as the circumferential groove, and is parallel to the optical axis. An optical axis direction groove different from the claw insertion / removal groove, which crosses the circumferential groove, wherein a circumferential length of the engaging claw is larger than a width of the optical axis direction groove. 7. A zoom lens barrel comprising a pair of cylindrical members having mutually different diameters, the relative rotation being free and the relative movement in the optical axis direction being impossible. The coupling means is provided on one of the inner peripheral surface of the large-diameter cylindrical member and the outer peripheral surface of the small-diameter cylindrical member at different positions in the optical axis direction, at least about the optical axis. Two circumferential grooves; and the other of the inner peripheral surface of the large-diameter cylindrical member and the outer peripheral surface of the small-diameter cylindrical member,
Protruded in the radial direction at different positions in the optical axis direction corresponding to the at least two circumferential grooves. Each circumferential groove is slidable in the circumferential direction and relatively immovable in the optical axis direction. A zoom lens barrel comprising: at least two engaging claws that engage with each other.